Unionville Center, Ohio, sits in USDA hardiness zone 6a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Well-matched crops include cabbage, hazelnut, lavender, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in Unionville Center, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Unionville Center lot. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Unionville Center — soil, climate, flood, and parcel records. How we handle your address.
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Unionville Center — the short answer
Unionville Center, Ohio: USDA zone 6a, about 209 days between hard freezes, across 101 acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 8
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 3
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~209
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 101 acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 6a is Unionville Center's average, not your lot's — a low corner or a tree line moves it. Against Unionville Center's 209-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Unionville Center
Each reading below is measured for Unionville Center itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredUnionville Center runs about 209 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredUnionville Center sits in USDA hardiness zone 6a.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Unionville Center is in
Unionville Center sits in the Eastern Corn Belt Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Unionville Center's own centroid rather than borrowed from Union County.
What Grows in Unionville Center
Every plant below cleared Unionville Center's own zone 6a and its 209-day season. Each card opens that plant's Ohio profile. How we score.
Is it too late to plant in Unionville Center?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 11; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 8 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 3 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
Documented around Unionville Center
Spotted lanternfly documented 18 miles from Unionville Center, first recorded 2022. What to watch for.
What's on the federal record near Unionville Center
Closest first, within ~10 miles of Unionville Center. Listing isn't leaking, and distance isn't exposure.
- HILBERT HISTORICAL CENTERUnderground Storage Tanks · 550 ft
- PLAIN CITY AUCTIONUnderground Storage Tanks · 900 ft
- MERRILL NICOLUnderground Storage Tanks · 2.2 mi
- ROBERT L. MITCHELLUnderground Storage Tanks · 2.2 mi
- MIDDLEBURG SVC CENTERUnderground Storage Tanks · 2.7 mi
- FAIRBANKS LOCAL SCHOOL DISTRICTUnderground Storage Tanks · 3.2 mi
- D.J. FEEDSUnderground Storage Tanks · 3.6 mi
- RANCO NORTH AMERICABrownfields · 3.8 mi
- RANCO NORTH AMERICAToxics Release Inventory · 3.8 mi
- BONDED #1142Underground Storage Tanks · 3.8 mi
- COLLISION CENTER THEBrownfields · 3.8 mi
- MARYSVILLE CITY PWSPFAS · 3.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Unionville Center's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Unionville Center.
Total Sites
202
within ~10 miles of Unionville Center
Risk Level
Elevated
Highest-severity
4 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Unionville Center
Severity Distribution
within ~10 miles of Unionville Center
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Unionville Center, Superfund runs higher than the national average — 4 sites within ~10 miles of Unionville Center. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Unionville Center
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Unionville Center average
Your land is one point inside Unionville Center
Everything above resolves to Unionville Center as a whole — one PHZM band and one 28°F frost record, read across 101 acres. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at town scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better local average.
Your Lot vs the Unionville Center Average
Unionville Center Average
- ●USDA Zones 6a, averaged across Unionville Center
- ●One soil character for all of Unionville Center
- ●Frost dates read at Unionville Center's scale: Apr 8 to Nov 3
YOUR Parcel
- ✓Your exact zone, not Unionville Center's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Unionville Center
Pull a site-specific report for your exact address in Unionville Center, Ohio — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Unionville Center averages can't show:
We read public map data around Unionville Center — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Unionville Center average
How we know this about Unionville Center
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Unionville Center’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Unionville Center
When does frost risk typically end in Unionville Center?
The last hard freeze (28°F) in Unionville Center typically lands around Apr 8, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about Apr 29.
When is the first frost in Unionville Center?
The first hard freeze (28°F) in Unionville Center typically arrives around Nov 3, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 20, so the watching starts about Oct 4 — about 209 days after the spring freeze cleared.
How long is the growing season in Unionville Center?
Measured between 28°F hard freezes, Unionville Center sees about 209 frost-free days — roughly Apr 8 through Nov 3, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 29 to Oct 20, about 174 days.
Is the soil safe to grow vegetables in Unionville Center?
The federal record around Unionville Center is a meaningful one — 202 documented sites, mostly Underground Storage Tanks entries (102), the nearest Underground Storage Tanks record about 0.1 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in Unionville Center?
From about Oct 4 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Nov 3 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Nov 3. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Unionville Center's scale — its 6a band and its 209-day season. Your yard writes its own version of Unionville Center's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Unionville Center’s own scale
7 of the readings below were taken at Unionville Center's own scale — its own ~209-day season between 28°F freezes, the 101 acres it covers and 202 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Unionville Center's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Unionville Center's own 28°F hard-freeze dates, about Apr 8 and Nov 3 and the ~209-day span between themNOAA 1991–2020 Climate Normals
- 202 documented contamination sites on the federal record near Unionville Center, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Unionville Center's boundary and the 101 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~209-day seasonGrowable Ground crop-matching engine
- The ecoregion at Unionville Center's own centroid, the Eastern Corn Belt PlainsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Unionville Centerlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Unionville Center's 101 acres read through its county's SSURGO summaryfrom Union County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Union County
- The growing challenges every Ohio grower plans around — written at state scale, so they stay on the state guidefrom Ohio
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Union County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Unionville Center's 101 acreswhy one lot differs from the next →
- Which side of Unionville Center you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 101 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Unionville Center-wide figureread your own land →
More in Ohio
Wider growing context
What grows across OhioUnionville Center sits outside our named growing regions, so Ohio as a whole is its closest context here.
Nearby growing guides